1. Field of the Invention
The present invention relates to an apparatus for transmitting power by means of a chain, and more particularly, to an apparatus for transmitting power by means of a chain in which the chain is contacted with or wound on a sprocket over an angle not more than 180 degrees.
2. Description of the Prior Art
Apparatuses for transmitting power by means of a chain have been widely used as power transmitting apparatus in various industrial fields primarily because no slippage occurs between a chain and the associated sprockets. Such a chain drive is equipped with a chain tensioning device which applies a suitable magnitude of tension to the stretched chain and absorbs the slackness thereof.
The chain tensioning device of the type described above utilizes the force of a spring to put the chain in a suitably taut condition and to absorb its slankness at times when the degree of slackness is small. To cope with the slackness of the chain which is caused by its elongation with age, the magnitude of tension applied to the chain is adjusted so that it remains constant by periodically changing the position at which the chain tensioning device is installed. The operation of shifting the position at which the chain tensioning device is installed includes removal of a cover and disassembly of the parts arranged on the periphery of the power transmitting apparatus. This is a troublesome but necessary operation because without it a close engagement between the chain and the associated sprockets cannot be maintained and damage of the chain or the teeth of the sprockets will result if this work is neglected.